05000366/LER-2020-001, Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La)
| ML20062F391 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 03/02/2020 |
| From: | Dean E Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-20-0230 LER 2020-001-00 | |
| Download: ML20062F391 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(1) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 3662020001R00 - NRC Website | |
text
A Southern Nuclear E. D. Dean Ill Vice President - Plant Hatch MAR 0 2 2020 l'hulll dwin I Hld<h I IU:!X Hat'h l'arkw<ty 1\\nnh llaxlcy, GA 1 1513
~ 12 517 ~xw 1ul 912 11\\1\\ 2077 fax Docket Nos.: 50-366 NL-20-0230 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Unit 2 Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La)
Ladies and Gentlemen:
In accordance with the requirements of 10 CFR 50.73 (a)(2)(i)(B). 10 CFA 50.73 (a)(2)(ii)(A), and 10 CFR 50.73 (a)(2)(v)(C). Southem Nuclear Operating Company hereby submits the enclosed Licensee Event Report.
This letter contains no NRC commitments. If you have any questions, please contact the Hatch Licensing Manager, Jimmy Collins at 912.537.2342 Respectfully submitted, r!lfl~
E. D. Dean Vice President - Hatch EDD/JEUSCM Enclosure: LEA 2020-001 -00 Cc:
Regional Administrator, Region II NRR Project Manager-Hatch Senior Resident Inspector-Hatch RTYPE: CHA02.004
Edwin I. Hatch Nuclear Plant Unit 2 Licensee Event Report 2020-001-00 Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La)
Enclosure LER 2020-001-00
NRC FORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO, 3160~104 EXPIRES: 03131/2020 (04-2018)
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3.Page Edwin I. Hatch Nuclear Plant Unit 2 05000 366 1
OF 3
- 4. nue Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La)
- 5. Event Date
- 6. LER Number
- 7. Report Date B. Other Facilities Involved Month O.y Year Year I Sequontlal I Rev Monll\\
Day Year oclllty Name Docket Number Numb.,.
No.
05000 01 2020 2020 001 00 3 :l.
Foclllty Nome Docket Number 04 21111..()
05000
- 9. Operating Mode
- 11. This Report Is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply) 0 20.2201(b) 0 20.220J(a)(3)(1) 0 50.73(a)(2)(ii)(A) 0 S0.73(a)(2}(Yiii)(A) 0 20.2201(d) 0 20.2203(a)(3)(ii)
D 50 73(a)(2)(ii)(B}
D 50.73(a)(2}(viij)(B) 1 D 20.2203(a)(1) 0 20.2203(a)(4)
D 50 73(a)I2)(iii)
D 50.7J(a)(2)(1x)(A) 0 20.2203(a}(2)(i) 0 50.36(c)(1)(1)(A)
D sa. 73(aJ(2)(iv)(A)
D 50,73(a)(2)(x)
- 10. Power Level 0 20.2203(a)(2)(ii}
0 50.36(c)(1)(1 )(A)
D 50,73(a](2)(v)(A)
D 73.71(a)(4) 0 20.2203(a}(2)(ill) 0 50.36(c)(2)
D S0.73(a)(2)(v)(B) 0 73.71(a)(5) 0 20 220J(a)(2}(iv)
D 50.46(8)(3)(11) 0 50,73(a)(2)(v)(C) 0 73.77(8)(1) 100 0 20 2203(a}(2)(v)
D 50.73(a)(2)(1)(A)
D 50.73(a)(2)(v)(D) 0 73.n(a)(2)(1)
D 20.2203(a)(2)(vi)
IZ] 50.7J(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 73.77(a)(2)(iQ D 50.73(a)(2)(i)(C)
D Other (Specify In Abstract below or In NRC Form 366A)
- 12. licensee Contact forthls LER licensee Contact Telephone Number (Include Area Code)
Jimmy Collins-Licensing Manager 912-537-2342 C.UIO Syatem I Cois"v""' I Manutac1u~
Reportable to ICES I Cauao I Syalem I Component Monulac1um I Reportable to ICES X
BB F130 y
- 14. Supplemental Report Expected Monllt Day Year 0 v.. (If yes, complete 15. Elcpected Submission Date)
[Z] No
- 15. Expected Submission Date Abstract (Limit to 1400 spaces, I.e., approximately 14 single-spaced typewritten lines)
On January 4, 2020 at 1109 EST, with Unit 2 operating at 100% rated thermal power, it was determined that the maximum allowable primary containment leakage rate (La) as defined in 10CFR50, Appendix J, "Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors", had been exceeded under postulated accident conditions.
Engineering troubleshooting efforts identified the degraded primary containment penetration and noted that leakage past two primary containment isolation valves (PCIVs) was causing La to be exceeded under postulated accident conditions. Additional valves downstream of the PCIVs were closed to retum primary containment back to operable status.
The cause of the PC IV failures is currently unknown and will be determined during valve disassembly during a planned outage.
At that time, the PCIVs will be repaired and returned to operable status.
NRC FORM 366 (04*2018)
CORRECTIVE ACTIONS
During an upcoming planned outage, the referenced PCIVs will be repaired and returned to operable status.
PREVIOUS SIMILAR ISSUES On February 7, 2017, with Unit 2 in a refueling outage, the same drywell ventilation penetration inboard isolation valve failed LLRT. On February 19, 2017, while still in the refueling outage, the same drywell ventilation penetration outboard isolation valve failed LLRT. This condition represented a failure of the associated penetration to maintain primary containment integrity due to both PCIVs In this penetration flow path exceeding La.
The cause of the PCIVs exceeding La was attributed to inadequate conditions related to the disc sealing ring that was found on both valves. Corrective actions included replacing the ring assemblies and adjusting the set screws on both PCIVs. A satisfactory LLRT was subsequently performed for both valves. Page 3
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